It is known that, in sports and competition bicycles using the so-called shoe brakes, the distance between the two brake shoes, which has to be very small in order to obtain a prompt and efficient braking, is normally less than the largest transversal dimension of the tire, and this prevents an easy wheel removal.
On the other hand, it is highly desirable in all the sports bicycles, and even essential in competition bicycles, for the wheels to be removed in an extremely easy and fast manner. Various expedients have thus been worked out in order to obtain a quick opening of the brake shoes allowing, in case of need, to remove the wheel without meeting any obstacles on the part of the brakes.